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Possible to Mod a Taito F3 Board for Better Sync Compatibility?

ShootTheCore

ShootTheCore

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The Taito F3 arcade board is well-known for outputting a strange sync signal. Upscalars like the OSSC and Framemeister often have trouble syncing with it, and CRTs often require drastic adjustments to the picture alignment and geometry. My personal F3 board will only sync with a Framemeister, and a friend's board is having trouble even syncing with that.

I'm curious if there is a way to mod the F3 to bring it's sync more into line with other arcade boards? Thoughts?
 
I think you'd need to nail down exactly what is "wrong" with the F3's sync signal before you can really devise a solution to fix it.

From reading that eBay listing it sounds like what that's doing is simply cleaning up a noisy or otherwise hard to read sync signal (maybe one without clearly defined rising and falling edges), but is that really what the F3 needs or is the problem something else.

I don't have an F3 myself yet (still waiting for it to arrive) so I can't do any testing at the moment but I've heard people talking about it the sync problems being related to the front/back porch and also causing the image to be off-center.

i would think that would need more than a simple sync cleaner.

really the best would be to map out the F3's sync signal with a scope and compare it to a system that runs the same resolution but without sync problems. Then once you've clearly identified the problem can you work on a solution.
 
twistedsymphony said:
really the best would be to map out the F3's sync signal with a scope and compare it to a system that runs the same resolution but without sync problems. Then once you've clearly identified the problem can you work on a solution.
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I agree. I have enough know-how to map out the sync signals with an oscilloscope, but I don't have the electrical engineering knowledge on what to do with building a correction circuit afterward. If I mapped out the signals and posted them on here, would that be of any use to someone that does have the necessary know-how?
 
Would the JROK sync cleaner help out? That's designed for supergun use which may be exactly what you need?
 
Also look into the Taito Jamma Kit scaler as it has a setting for F3 motherboards with perfect sync maybe that can tell you what they are doing with the signal from the F3.
 
I noticed i had to find a new 'sweet point' for my VI2500 (don't laugh!) chassis when i added in the F3, and it took a little bit of comparing the 6 boards on the system to find a point where all of them were happy. It DOES appear slightly off centre when compared to some other boards, but it's nothing to get upset over when the lights are down, and You are in the zone.

The only system that caused drama when comparing it to the settings of the F3 was my MVS. It is right on the edge of cycling, and if the monitor starts the day on the F3, switching to the MVS can give a useless cycling mess. Starting from cold to the MVS and then switching to the F3 is fine. My MVS has always been a bit twitchy anyway. Probably needs capping.

So, the F3 is NOT a 'plug & play on any previously perfect with another board monitor' for me, but it's well within the realms of possibility to dial it in perfectly, especially if it's running solo on the cabinet, and You have the time.

Not sure how it would fare with a SCART or RGB setup, as alot of TV chassis get very pissed off at the slightest imperfection, and throw up onscreen garbage, or go into standby if things get too far out of range. Nothing more annoying then the "AV" overlay appearing in the top corner every 30 seconds!! grrrrr......
 
OK, I can add to this as I have had big issues with me television. The only things I have found that really work are these.

ONLY this though, not a similar type!!! This one understands RGB rather than just composite: https://www.amazon.co.uk/gp/product/B00W9DJMNC/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

The other one is connected to my supergun: New RGB CGA EGA YUV to VGA HD Video Converter Board Moudle HD9800 GBS8200 BS from ebay.

I hope it can help, as the Taito F3 is really annoying to get right. If you have an Xbox One, then it will take the HDMI in and make the screen 4:3. A faff! Yes. Worth it? Absolutely.
 
I've found you almost always want to use a lm1881 with the gonbes scalers, whether you think you do or not. Clears up tons of problems.
 
Derick2k said:
Awesome, gonna try to place an order.
Thanks!
Click to expand...
let us know how it goes. I'd be inclined to add this if it fixes the horizontal alignment issue so I don't have to re-adjust everytime I swap out the F3.
 
I'd also be interested to know if you can use that CSync cleaner linked above to fix the horizontal alignment of the F3 on a CRT.
 
I’m interested to know if this fixes the alignment issue as well. My only sore point with the F3 multi, but in no way the fault of the multi.
 
SmokeMonster said:
Plugging in a HAS Supergun would regenerate the sync. That would be a mod-less option. @RGB
Click to expand...
I already use a HAS SuperGun with the sync regenerator enabled, and it doesn't work with three F3 boards I've tried and my OSSC. It'll sync with my Framemeister with either the straight sync off the board or the sync regenerator enabled, but the OSSC won't sync with either.

I've been posting for a while over at the OSSC VideoGamePerfection forums on it, and marqs said that he'd look into it. Unfortunately, his F3 synced perfectly with his setup (no idea what SuperGun he's using), and it doesn't sound like he's going to look into it any further. So I'm at a dead end with my setup unless I want to start probing the lines with an oscilloscope for myself to figure out the problem.

For now, I just always use the Framemeister with my F3.
 
I've done some H shift before with extron sync stabilizers, but I never had luck at 15k on that particular device. It's a shame because most of my other extron stuff does 15k just fine even if it says 31k minimum.
 
I also forgot to mention that in addition to the Sync Regenerator on my HAS, I also have a Sync Cleaner upline in my gscartsw switch. Enabling or disabling the sync cleaner doesn't help me with getting the F3 to sync with the OSSC either.

Maybe there's something weird with the SCART cable I'm using to go from my HAS to the gwscartsw. But every other board I own syncs just fine, so <shrug> ... I dunno.

EDIT: marqs and another user over at the VideoGamePerfection forum say that the F3 syncs more reliably with the OSSC if you use the OSSC's VGA input. But I don't know what cable I'd use to go from the HAS's DIN output to VGA. @RGB what are your thoughts on outputting HAS to VGA?
 
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My Japanese is a bit rusty :P but here's the instructions for the csync cleaner:

http://www.ntls.jp/manual/CSyncCleaner_Manual.pdf

1QYqg6f.png


コネクタ(P2)について
未実装になっているコネクタ(P2)からは HSync と VSync と GND が出力されています。他の回路へ流用するために出力していますが、コネクタは取り付けていません。2.5mm ピッチの適当な物を付けるか、JST NH の 3pin(B3P-SHF-1AA[垂直], BS3P-SHF-1AA[直角])などを取り付けてください。

HSync, VSync, and GND are output from the connector (P2) which is not mounted yet. Flow to other circuitsWe are outputting it for use but connectors are not installed. Attach a suitable object of 2.5 mm pitch,JST NH 3 pin (B3P - SHF - 1AA[Vertical], BS3P - SHF - 1AA [Right Angle]) and so on.
 
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